Sphygmomanometer cuff capable of blocking blood flow favorably even with small width in wrapping direction

ABSTRACT

A bladder incorporated in a cuff includes an outer wall located at the outer side, an inner wall located at the inner side, side walls connected to both side ends of the outer wall and the inner wall in the wrapping direction, and folded inward of the bladder, and a joint connecting the side walls inside the bladder. A sphygmomanometer cuff is provided that can maintain the former configuration even when inflated or deflated without change in the width even if the bladder is inflated, and that does not dilate in the width direction when inflated.

REFERENCE TO RELATED APPLICATION

This application is a continuation of Ser. No. 09/781,977, filed Feb.14, 2001, now U.S. Pat. No. 6,527,727 which claims priority fromJapanese Patent Application No. 2000-39036, filed Feb. 17, 2000.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a cuff for a sphygmomanometer,particularly to a sphygmomanometer cuff wrapped around the region ofmeasurement such as the upper arm or wrist used to increase the pressureat that region to measure blood pressure.

2. Description of the Background Art

FIG. 6 is a perspective view of an entire sphygmomanometer cuff.Referring to FIG. 6, a sphygmomanometer cuff 70 includes an outer cuffpiece 71, an inner cuff piece 72, a bladder 73 provided inside aband-like bladder formed of outer cuff piece 71 and inner cuff piece 72,and a clip plate 74 arranged outside bladder 73 to suppress the outwardswell of bladder 73 and maintain a predetermined curved configuration inan elastic manner. Hook-and-loop fasteners 75 and 76 are provided atouter cuff piece 71 and inner cuff piece 72, respectively. Cuff 70 isfastened to the measurement region in a wrapped-around manner byhook-and-loop fasteners 75 and 76.

Such a cuff 70 is provided in a wrist sphygmomanometer as shown in FIG.7, for example, and attached to a sphygmomanometer unit 80.

Bladder 73 used in the aforementioned cuff 70 includes an outer wall 61and an inner wall 62, as shown in FIG. 4 (the upper portion correspondsto a deflated state and the lower portion corresponds to an inflatedstate). Walls 61 and 62 are fixed with each other by melting or the likeat both ends 63 in the wrapping direction.

Inflation of bladder 73 results in a smaller width of bladder 73 (thedimension perpendicular to the wrapping direction). Pressure caused byinflation of bladder 73 may not be applied sufficiently to the arterylocated in the measurement region around which cuff 70 is wrapped todegrade the reliability of the blood pressure measurement precision.Particularly in the case of cuffs for wrist sphygmomanometers, there aremany disadvantages in blocking the flow of blood since there are moretendons and the like at the wrist than at the upper arm. Therefore, thecuff for a wrist sphygmomanometer requires a higher performance ofblocking blood flow than that of the cuff for the upper arm. It isdifficult to apply sufficient pressure to the region where blood flow isto be blocked and the blood flow could not be blocked favorably if theconventional cuff configuration was used in which the width becomessmaller.

Japanese Patent No. 2840075 B2 discloses a cuff band for a wristsphygmomanometer as schematically shown in FIG. 5 (the upper portioncorresponds to a deflated state and the lower portion corresponds to aninflated state). Referring to FIG. 5, a blood blocking cuff (bladder) 50is formed in a bladder configuration with two inner and outer cuffpieces 51 and 52 and side walls 53. Side wall 53 serving to inflateblood blocking cuff 50 in the thickness direction by the introduction ofair into blood blocking cuff 50 is provided in a direction (thedirection indicated by the arrow in FIG. 5) crossing the direction ofinner cuff piece 52 wrapping around the wrist.

Since side walls 53 project outwards when air is introduced into bloodblocking cuff 50, the width of blood blocking cuff 50 does not changealthough it is inflated. However, there is a problem that, after air isdischarged, side walls 53 will not return to the original configurationof inward folded state.

SUMMARY OF THE INVENTION

In view of the foregoing, an object of the present invention is toprovide a sphygmomanometer cuff that can maintain its formerconfiguration in both the inflated and deflated state without change inthe width even if the bladder is inflated and without expanding in thewidth direction when inflated.

To achieve the above object, the sphygmomanometer cuff of the presentinvention includes a bladder that inflates and deflates by the input andoutput of a fluid. The bladder includes an outer wall located at theouter side, an inner wall located at the inner side, a side wallconnected to both ends in the wrapping direction of respective outer andinner walls, and folded inward in the bladder, and a joint coupling theside walls inside the bladder.

Since the bladder includes a joint that couples both side walls withinthe bladder in addition to the outer wall, inner wall and side walls inthis cuff, the bladder maintains its configuration in which both sidewalls are folded when there is no fluid (water, air, or the like) in thebladder. Introduction of a fluid into the bladder causes the side wallsto dilate outward from the folded state. However, since side walls areconnected by the joint, the side walls do not project outwards, and thecuff is inflated in the direction of the thickness as the side wallsextend substantially straight in the direction of the thickness of thecuff. Therefore, the bladder does not expand in the direction of thewidth when inflated. The width of the bladder hardly differs from thatprior to inflation. When the fluid in the bladder is discharged, theside walls easily return to the folded state by virtue of the joint asthe outer wall and the inner wall approximate each other and iseventually restored to the state prior to inflation.

By setting the side walls harder than the outer and inner walls in theabove structure, the balance of weight of the bladder is improvedparticularly during inflation, so that pressure can be applied morestably at the measurement region with the cuff.

The details of setting both side walls harder than the outer wall andthe inner wall will be described here. In the case where the side wall,the outer wall, and the inner wall are all to be formed of the samematerial, for example using a soft vinyl chloride sheet of the sametype, the thickness of the side wall is set to 0.4 mm and the thicknessof the outer wall and the inner wall is set to 0.2 mm, by way ofexample. Alternatively, when different materials are to be used, thetype and thickness of each material is to be selected appropriately sothat the side wall is harder than the outer wall and the inner wall.

The foregoing and other objects, features, aspects and advantages of thepresent invention will become more apparent from the following detaileddescription of the present invention when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the portion of the bladder incorporatedin a sphygmomanometer cuff according to an embodiment of the presentinvention.

FIG. 2 is a partial sectional view of the bladder incorporated in asphygmomanometer cuff attached to the upper arm and the wrist.

FIG. 3 is a perspective view of the portion of a bladder incorporated ina sphygmomanometer cuff according to another embodiment of the presentinvention.

FIG. 4 is a partial perspective view of a conventional bladdercorresponding to a deflated status (upper portion) and an inflated state(lower portion).

FIG. 5 is a partial perspective view of another conventional bladdercorresponding to a deflated status (upper portion) and an inflatedstatus (lower portion).

FIG. 6 is a perspective view showing an example of a general bladder.

FIG. 7 is a perspective view of a wrist sphygmomanometer with a bladdersuch as that of FIG. 6.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention will be described hereinafter withreference to the drawings.

Referring to FIG. 1, a bladder 10 incorporated in a sphygmomanometercuff includes an outer wall 11 located at the outer side, an inner wall12 located at the inner side, side walls 13 and 14 connected torespective side ends 11 a and 11 b, 12 a and 12 b in a directioncrossing the wrapping direction of outer and inner walls 11 and 12 (thedirection indicated by the arrow in FIG. 1), and folded inward ofbladder 10, and a joint 15 coupling side walls 13 and 14 inside bladder10. Side wall 13 is fixed to side ends 11 a and 12 a of outer and innerwalls 11 and 12 by an adhesive, by melting or the like. Similarly, sidewall 14 is fixed to side ends 11 b and 12 b of outer and inner walls 11and 12 by an adhesive, by melting or the like.

In bladder 10, side wall 13 is formed of pieces 16 and 17. Piece 17 isprovided integrally with joint 15. Piece 16 is fixed at the borderbetween joint 15 and piece 17 by an adhesive, by melting or the like.Similarly, side wall 14 is formed of pieces 18 and 19. Piece 19 isprovided integrally with joint 15. Piece 18 is fixed at the borderbetween joint 15 and piece 19.

Bladder 10 has holes 20 provided at an appropriate interval in joint 15.This hole 20 provides communication between the chambers in bladder 10partitioned into two by joint 15. Air communication is improved by theformation of hole 20.

When air is delivered into bladder 10 of above-described structure,outer wall 11 and inner wall 12 inflate in the direction of thickness ofbladder 10 by air pressure, whereby side walls 13 and 14 extend in thedirection of thickness. However, side walls 13 and 14 extend tosubstantially an upright status at most without projecting outwardssince side walls 13 and 14 are connected by joint 15. Therefore, bladder10 does not expand in the direction of the width during inflation. Thewidth of bladder 10 hardly differs from that prior to inflation. Whenair is discharged from bladder 10, side walls 13 and 14 easily return tothe folded state by joint 15 as outer wall 11 and inner wall 12 comecloser to each other to be eventually restored to the status prior toinflation.

FIG. 2 is a partial sectional view of the bladder when thesphygmomanometer cuff with the bladder of FIG. 1 is wrapped around theupper arm and the wrist. Referring to the upper portion in FIG. 2,bladder 10 a will apply pressure flatly around the arm at the upper armportion indicated by the arrow in FIG. 2 by virtue of joint 15 a andhole 20 a.

Referring to the lower portion of FIG. 2 where the cuff is wrappedaround the wrist, bladder 10 b applies pressure flatly around the wristat the portion indicated by the arrow in FIG. 2 by virtue of joint 15 band hole 20 b.

As a result, sufficient pressure can be applied at the region ofinterest to block the flow of blood favorably.

In this bladder 10, the balance of weight of bladder 10 during theinflation status can be improved by setting side walls 13 and 14 harderthan outer wall 11 and inner wall 12. Pressure can be applied morestably at the measurement region using the cuff with bladder 10.

FIG. 3 is a partial perspective view of a bladder incorporated in asphygmomanometer cuff according to another embodiment of the presentinvention.

Referring to FIG. 3, this bladder 30 includes an outer wall 31, an innerwall 32, side walls 33 and 34, and a joint 35. Side wall 33 is formed ofpieces 36 and 37. Pieces 36 and 37 are fixed integrally, and fastened tothe end of joint 35. Similarly, side wall 34 is formed of pieces 38 and39. Pieces 38 and 39 are fixed integrally, and fastened to the end ofjoint 35.

Joint 35 of the present embodiment does not form a band as joint 15 ofbladder 10 of the previous embodiment. A plurality of joints 35 (threejoints in this embodiment) are fixed to side walls 33 and 34 atappropriate intervals, whereby side walls 33 and 34 are connected byjoints 35. Hole 40 formed between joints 35 functions as an air channel(communication). Bladder 30 of the present embodiment providesadvantageous effects similar to those of bladder 10.

Although the shape of the hole is preferably circular, a hole in theshape of a polygon can also be used provided that a curved portion isformed so that stress is not concentrated at the corner.

Instead of forming a hole in joint 15, joint 15 having a meshconfiguration all over can be employed.

In the above embodiments, the outer wall, the inner wall, and the sidewalls are produced individually and then fastened. Alternatively, abladder having the outer wall, the inner wall, the side walls, and thejoint formed integrally by injection molding can be used.

Although the present invention has been described and illustrated indetail, it is clearly understood that the same is by way of illustrationand example only and is not to be taken by way of limitation, the spiritand scope of the present invention being limited only by the terms ofthe appended claims.

What is claimed is:
 1. A sphygmomanometer cuff that includes aninflatable bladder and is adapted to wrap around a region of a personalong a predetermined wrapping direction, the bladder comprising: afirst wall located at a first side, a second wall located at a secondside opposite the first wall, a pair of side walls connected to sideends of the first wall and the second wall in a direction crossing apredetermined wrapping direction, the side walls being foldable, and ajoint connecting foldable portions of the side walls.
 2. Thesphygmomanometer cuff according to claim 1, wherein said side walls areharder than the first wall and the second wall.
 3. The sphygmomanometercuff according to claim 1, wherein a hole is provided in said joint. 4.The sphygmomanometer cuff according to claim 3, wherein a plurality ofsaid holes are provided.
 5. The sphygmomanometer cuff according to claim3, wherein said hole is a round hole.
 6. The sphygmomanometer cuffaccording to claim 1, wherein said bladder is formed integrally.
 7. Asphygmomanometer cuff including a bladder that inflates or deflates byintroducing or discharging fluid into or from the bladder, the bladdercomprising: a first plane adapted to abut against a wrist or an arm, andextending in a first direction which is a circumferential directionthereof, a second plane opposite the first plane, wherein the first andsecond planes have a first dimension in a second direction crossing thefirst direction, third and fourth planes opposite each other to connectthe first and second planes, and a connection member connectingmid-portions of the third and fourth planes.
 8. The sphygmomanometercuff according to claim 7, wherein a hole is formed in the connectionmember.